Electrical Stability and Piezoresistive Sensing Performance of High Strain-Range Ultra-Stretchable CNT-Embedded Sensors

Abstract

Highly flexible and stretchable sensors are becoming increasingly widespread due to their versatile applicability in human/robot monitoring sensors. Conductive polymeric composites have been regarded as potential candidates for such sensors, and carbon nanotubes (CNTs) are widely used to fabricate such composites. In the present study, CNT-embedded high flexible sensors were fabricated using a facile three-roll milling method, which mitigates the drawbacks of the conventional fabrication methods. CNTs content varied between 0.5 and 4.0 wt.%, and the percolation threshold range was obtained via conductivity/resistivity values of the fabricated sensors. Following this, the electrical stability of the sensors was examined against the various DC and AC signals. Furthermore, the fabricated sensors were stretched up to 500% strain, and their sensitivity against varying strain amplitudes was investigated in terms of the change in resistance and gauge factors. Lastly, the fabricated sensors were applied to human fingers for monitoring finger bending and releasing motions to validate their potential applications. The experimental results indicated that these sensors have a percolation threshold of around 2% CNTs content, and the sensors fabricated with 2 to 4% CNTs content showed measurable resistance changes against the applied strain amplitudes of 50–500%. Among these sensors, the sensor with 2% CNTs content showed the highest sensitivity in the studied strain range, exhibiting a resistance change and gauge factor of about 90% and 1.79 against 50% strain amplitude and about 18,500% and 37.07 against 500% strain amplitude, respectively. All these sensors also showed high sensitivity for finger motion detection, showing a resistance change of between 22 and 69%.

Self-Monitoring Performance of 3D-Printed Poly-Ether-Ether-Ketone Carbon Nanotube Composites

“…The mixing process is also a crucial factor in the determination of the resulting electrical properties. There are several processes to obtain a good dispersion of CNTs, including ultra-sonication with a polymeric dispersant and mechanical mixing (i.e., twin screw mixer, three-roll milling [ 35 ].…”

Effects of Carbon Nanotube and Graphene Oxide Incorporation on the Improvements of Magneto-Induced Electrical Sensitivity of Magneto-Rheological Gel

“…As seen in Figure 3 , the electrical impedance of all samples decreased as the input frequencies increased. This can be explained from the properties of capacitance which are inversely proportional to the input frequency, and this phenomena can be found in the previous studies [ 25 ]. Third, it can be established that the electrical impedances of MRG samples regardless of the added conductive fillers decreased as the applied magnetic field increased.…”

A Comprehensive Study on EMI Shielding Performance of Carbon Nanomaterials-Embedded CFRP or GFRP Composites

“…The three-roll mixer has been used to enhance homogeneous dispersion of nanomaterials in polymer matrix materials, and it has proved an increase in the reliability of the performance and characteristics of the composites [ 15 ]. In addition, this method requires a minimal amount of solvent and improves economic efficiency [ 19 , 20 , 21 ]. However, the three-roll milling process may entail disadvantage such as damages in nano-structures of the CNMs due to repeatedly applied mechanical forces.…”